The stress corrosion behavior of four alloys of aluminum has been investigated. Using cantilever-loaded fatigue-cracked specimens, the crack propagation characteristics of 7178-T6, 2014-T6, 2024-T351, and 7075-T6 aluminum alloys were determined. The results are interpreted in terms of fracture mechanics parameters. Where susceptibility to stress corrosion exists, the rate of crack propagation is dependent upon stress intensity and environment. A method is also presented to obtain threshold values of stress intensity for stress corrosion attack with minimal experimental effort. The aqueous environments used were immersion in distilled water, immersion in 3 1/2 per cent sodium chloride, and alternate immersion in salt solution and air. The cantilever technique is evaluated and the results compared to other testing methods.